The present invention concerns dust-collecting systems for circular knitting machines, of the type comprising at least one suction nozzle mounted to travel in an orbit coaxial with the needle cylinder of the machine and collect dust and fluff from the annular loop-forming zone of the circular knitting machine.
German Democratic Republic Pat. No. 34,664 of Jan. 15, 1965 discloses such a dust-collection system, in which an annular channel-defining housing coaxial with the needle cylinder defines an annular suction channel connected to a suction source. Part of the channel-defining housing rotates under the action of a drive mechanism and mounts the dust-collecting suction nozzles. In that conventional system, the annular channel-defining housing is located vertically higher than the annular loop-forming zone of the circular knitting machine; the suction nozzles extend downwardly from the annular channel-defining housing towards the loop-forming zone and accordingly suck dust and fluff upwards into the annular suction channel of the housing.
With such a conventional system, the location of the annular channel-defining housing vertically above the annular loop-forming zone, with the suction nozzles extending downwards from the housing to the loop-forming zone, has the effect of interfering with the yarn-feeding systems of the machine and interfering with access to the yarn-feeding systems of the machine. The dust-collecting system, due to its location and configuration, additionally interferes with freedom of access to the loop-forming instrumentalities and cam system of the machine. Additionally, in that type of system, the rotating part of the channel-defining housing rides on exposed rollers, and the rotating part of the channel-defining housing is driven by a drive gear relative to which it cannot slip.